The objective of this study is to test the primary hypothesis that domestic pets (dogs and cats) can become colonized with strains of MRSA that are commonly associated with human infections, when they live in close contact with infected people. Current protocols for the treatment and prevention of recurrent MRSA infection in individuals or households do not consider a potential role for non-human animals to harbor the bacteria. However, it is known that close human contacts may be subclinically colonized with MRSA, and may serve as sources of re-infection to susceptible individuals. Subclinical colonization may persist for months to years in some individuals. The current veterinary literature and discoveries in our laboratory suggest that several species of animals are capable of being infected or colonized by strains of MRSA that are known to circulate either in the community or within healthcare facilities, and which cause serious skin and soft tissue infections of people. In Aim 1 we will determine the prevalence of MRSA on the skin and mucous membranes of domestic animals living in households with people that have confirmed positive MRSA clinical cultures. We hypothesize that prevalence of carriage by companion animals will approximate that reported for "close" human contacts of MRSA patients. In Aim 2 we will determine the molecular characteristics of human-animal paired isolates, and compare these characteristics across animal isolates. We hypothesize that companion animal MRSA isolates will be identical to those obtained from their owners suggesting direct transmission, that clonal clusters will be evident within human-animal populations, and that the prevalence of MRSA colonizing pets will vary by strain type (SCCmec Type). In Aim 3 we will identify human and animal-associated risk factors for MRSA colonization of pets. We hypothesize that the proximity of a pet animal to a person with MRSA infection (close versus casual contact) is a primary risk factor associated with pet colonization by MRSA. The human-animal bond is an undeniable facet of human health, both psychiatric and physical, and many people consider their pets to be an indispensable part of the family unit. It is a fact that humans and animals share germs, such as MRSA. Recognizing this fact and discovering ways to minimize its impact is imperative to the protection of public health: both human and animal.